/*
 * ipcp.c - PPP IP Control Protocol.
 *
 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The name "Carnegie Mellon University" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For permission or any legal
 *    details, please contact
 *      Office of Technology Transfer
 *      Carnegie Mellon University
 *      5000 Forbes Avenue
 *      Pittsburgh, PA  15213-3890
 *      (412) 268-4387, fax: (412) 268-7395
 *      tech-transfer@andrew.cmu.edu
 *
 * 4. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by Computing Services
 *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
 *
 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "netif/ppp/ppp_opts.h"
#if PPP_SUPPORT && PPP_IPV4_SUPPORT /* don't build if not configured for use in lwipopts.h */

/*
 * @todo:
 */

#if 0 /* UNUSED */
	#include <stdio.h>
	#include <string.h>
	#include <stdlib.h>
	#include <netdb.h>
	#include <sys/param.h>
	#include <sys/types.h>
	#include <sys/socket.h>
	#include <netinet/in.h>
	#include <arpa/inet.h>
#endif /* UNUSED */

#include "netif/ppp/ppp_impl.h"

#include "netif/ppp/fsm.h"
#include "netif/ppp/ipcp.h"

#if 0 /* UNUSED */
	/* global vars */
	u32_t netmask = 0;		/* IP netmask to set on interface */
#endif /* UNUSED */

#if 0 /* UNUSED */
	bool	disable_defaultip = 0;	/* Don't use hostname for default IP adrs */
#endif /* UNUSED */

#if 0 /* moved to ppp_settings */
	bool	noremoteip = 0;		/* Let him have no IP address */
#endif /* moved to ppp_setting */

#if 0 /* UNUSED */
	/* Hook for a plugin to know when IP protocol has come up */
	void (*ip_up_hook)(void) = NULL;

	/* Hook for a plugin to know when IP protocol has come down */
	void (*ip_down_hook)(void) = NULL;

	/* Hook for a plugin to choose the remote IP address */
	void (*ip_choose_hook)(u32_t*) = NULL;
#endif /* UNUSED */

#if PPP_NOTIFY
	/* Notifiers for when IPCP goes up and down */
	struct notifier* ip_up_notifier = NULL;
	struct notifier* ip_down_notifier = NULL;
#endif /* PPP_NOTIFY */

/* local vars */
#if 0 /* moved to ppp_pcb */
	static int default_route_set[NUM_PPP];	/* Have set up a default route */
	static int proxy_arp_set[NUM_PPP];	/* Have created proxy arp entry */
	static int ipcp_is_up;			/* have called np_up() */
	static int ipcp_is_open;		/* haven't called np_finished() */
	static bool ask_for_local;		/* request our address from peer */
#endif /* moved to ppp_pcb */
#if 0 /* UNUSED */
	static char vj_value[8];		/* string form of vj option value */
	static char netmask_str[20];		/* string form of netmask value */
#endif /* UNUSED */

/*
 * Callbacks for fsm code.  (CI = Configuration Information)
 */
static void ipcp_resetci(fsm* f);	/* Reset our CI */
static int  ipcp_cilen(fsm* f);	        /* Return length of our CI */
static void ipcp_addci(fsm* f, u_char* ucp, int* lenp); /* Add our CI */
static int  ipcp_ackci(fsm* f, u_char* p, int len);	/* Peer ack'd our CI */
static int  ipcp_nakci(fsm* f, u_char* p, int len, int treat_as_reject);/* Peer nak'd our CI */
static int  ipcp_rejci(fsm* f, u_char* p, int len);	/* Peer rej'd our CI */
static int  ipcp_reqci(fsm* f, u_char* inp, int* len, int reject_if_disagree); /* Rcv CI */
static void ipcp_up(fsm* f);		/* We're UP */
static void ipcp_down(fsm* f);		/* We're DOWN */
static void ipcp_finished(fsm* f);	/* Don't need lower layer */

static const fsm_callbacks ipcp_callbacks = { /* IPCP callback routines */
	ipcp_resetci,		/* Reset our Configuration Information */
	ipcp_cilen,			/* Length of our Configuration Information */
	ipcp_addci,			/* Add our Configuration Information */
	ipcp_ackci,			/* ACK our Configuration Information */
	ipcp_nakci,			/* NAK our Configuration Information */
	ipcp_rejci,			/* Reject our Configuration Information */
	ipcp_reqci,			/* Request peer's Configuration Information */
	ipcp_up,			/* Called when fsm reaches OPENED state */
	ipcp_down,			/* Called when fsm leaves OPENED state */
	NULL,			/* Called when we want the lower layer up */
	ipcp_finished,		/* Called when we want the lower layer down */
	NULL,			/* Called when Protocol-Reject received */
	NULL,			/* Retransmission is necessary */
	NULL,			/* Called to handle protocol-specific codes */
	"IPCP"			/* String name of protocol */
};

/*
 * Command-line options.
 */
#if PPP_OPTIONS
static int setvjslots(char**);
static int setdnsaddr(char**);
static int setwinsaddr(char**);
static int setnetmask(char**);
int setipaddr(char*, char**, int);

static void printipaddr(option_t*, void (*)(void*, char*, ...), void*);

static option_t ipcp_option_list[] = {
	{
		"noip", o_bool, &ipcp_protent.enabled_flag,
		"Disable IP and IPCP"
	},
	{
		"-ip", o_bool, &ipcp_protent.enabled_flag,
		"Disable IP and IPCP", OPT_ALIAS
	},

	{
		"novj", o_bool, &ipcp_wantoptions[0].neg_vj,
		"Disable VJ compression", OPT_A2CLR, &ipcp_allowoptions[0].neg_vj
	},
	{
		"-vj", o_bool, &ipcp_wantoptions[0].neg_vj,
		"Disable VJ compression", OPT_ALIAS | OPT_A2CLR,
		&ipcp_allowoptions[0].neg_vj
	},

	{
		"novjccomp", o_bool, &ipcp_wantoptions[0].cflag,
		"Disable VJ connection-ID compression", OPT_A2CLR,
		&ipcp_allowoptions[0].cflag
	},
	{
		"-vjccomp", o_bool, &ipcp_wantoptions[0].cflag,
		"Disable VJ connection-ID compression", OPT_ALIAS | OPT_A2CLR,
		&ipcp_allowoptions[0].cflag
	},

	{
		"vj-max-slots", o_special, (void*)setvjslots,
		"Set maximum VJ header slots",
		OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, vj_value
	},

	{
		"ipcp-accept-local", o_bool, &ipcp_wantoptions[0].accept_local,
		"Accept peer's address for us", 1
	},
	{
		"ipcp-accept-remote", o_bool, &ipcp_wantoptions[0].accept_remote,
		"Accept peer's address for it", 1
	},

	{
		"ipparam", o_string, &ipparam,
		"Set ip script parameter", OPT_PRIO
	},

	{
		"noipdefault", o_bool, &disable_defaultip,
		"Don't use name for default IP adrs", 1
	},

	{
		"ms-dns", 1, (void*)setdnsaddr,
		"DNS address for the peer's use"
	},
	{
		"ms-wins", 1, (void*)setwinsaddr,
		"Nameserver for SMB over TCP/IP for peer"
	},

	{
		"ipcp-restart", o_int, &ipcp_fsm[0].timeouttime,
		"Set timeout for IPCP", OPT_PRIO
	},
	{
		"ipcp-max-terminate", o_int, &ipcp_fsm[0].maxtermtransmits,
		"Set max #xmits for term-reqs", OPT_PRIO
	},
	{
		"ipcp-max-configure", o_int, &ipcp_fsm[0].maxconfreqtransmits,
		"Set max #xmits for conf-reqs", OPT_PRIO
	},
	{
		"ipcp-max-failure", o_int, &ipcp_fsm[0].maxnakloops,
		"Set max #conf-naks for IPCP", OPT_PRIO
	},

	{
		"defaultroute", o_bool, &ipcp_wantoptions[0].default_route,
		"Add default route", OPT_ENABLE | 1, &ipcp_allowoptions[0].default_route
	},
	{
		"nodefaultroute", o_bool, &ipcp_allowoptions[0].default_route,
		"disable defaultroute option", OPT_A2CLR,
		&ipcp_wantoptions[0].default_route
	},
	{
		"-defaultroute", o_bool, &ipcp_allowoptions[0].default_route,
		"disable defaultroute option", OPT_ALIAS | OPT_A2CLR,
		&ipcp_wantoptions[0].default_route
	},

	{
		"replacedefaultroute", o_bool,
		&ipcp_wantoptions[0].replace_default_route,
		"Replace default route", 1
	},
	{
		"noreplacedefaultroute", o_bool,
		&ipcp_allowoptions[0].replace_default_route,
		"Never replace default route", OPT_A2COPY,
		&ipcp_wantoptions[0].replace_default_route
	},
	{
		"proxyarp", o_bool, &ipcp_wantoptions[0].proxy_arp,
		"Add proxy ARP entry", OPT_ENABLE | 1, &ipcp_allowoptions[0].proxy_arp
	},
	{
		"noproxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
		"disable proxyarp option", OPT_A2CLR,
		&ipcp_wantoptions[0].proxy_arp
	},
	{
		"-proxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
		"disable proxyarp option", OPT_ALIAS | OPT_A2CLR,
		&ipcp_wantoptions[0].proxy_arp
	},

	{
		"usepeerdns", o_bool, &usepeerdns,
		"Ask peer for DNS address(es)", 1
	},

	{
		"netmask", o_special, (void*)setnetmask,
		"set netmask", OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, netmask_str
	},

	{
		"ipcp-no-addresses", o_bool, &ipcp_wantoptions[0].old_addrs,
		"Disable old-style IP-Addresses usage", OPT_A2CLR,
		&ipcp_allowoptions[0].old_addrs
	},
	{
		"ipcp-no-address", o_bool, &ipcp_wantoptions[0].neg_addr,
		"Disable IP-Address usage", OPT_A2CLR,
		&ipcp_allowoptions[0].neg_addr
	},

	{
		"noremoteip", o_bool, &noremoteip,
		"Allow peer to have no IP address", 1
	},

	{
		"nosendip", o_bool, &ipcp_wantoptions[0].neg_addr,
		"Don't send our IP address to peer", OPT_A2CLR,
		&ipcp_wantoptions[0].old_addrs
	},

	{
		"IP addresses", o_wild, (void*)& setipaddr,
		"set local and remote IP addresses",
		OPT_NOARG | OPT_A2PRINTER, (void*)& printipaddr
	},

	{ NULL }
};
#endif /* PPP_OPTIONS */

/*
 * Protocol entry points from main code.
 */
static void ipcp_init(ppp_pcb* pcb);
static void ipcp_open(ppp_pcb* pcb);
static void ipcp_close(ppp_pcb* pcb, const char* reason);
static void ipcp_lowerup(ppp_pcb* pcb);
static void ipcp_lowerdown(ppp_pcb* pcb);
static void ipcp_input(ppp_pcb* pcb, u_char* p, int len);
static void ipcp_protrej(ppp_pcb* pcb);
#if PRINTPKT_SUPPORT
static int ipcp_printpkt(const u_char* p, int plen,
                         void (*printer)(void*, const char*, ...), void* arg);
#endif /* PRINTPKT_SUPPORT */
#if PPP_OPTIONS
	static void ip_check_options(void);
#endif /* PPP_OPTIONS */
#if DEMAND_SUPPORT
	static int  ip_demand_conf(int);
	static int  ip_active_pkt(u_char*, int);
#endif /* DEMAND_SUPPORT */
#if 0 /* UNUSED */
	static void create_resolv(u32_t, u32_t);
#endif /* UNUSED */

const struct protent ipcp_protent = {
	PPP_IPCP,
	ipcp_init,
	ipcp_input,
	ipcp_protrej,
	ipcp_lowerup,
	ipcp_lowerdown,
	ipcp_open,
	ipcp_close,
#if PRINTPKT_SUPPORT
	ipcp_printpkt,
#endif /* PRINTPKT_SUPPORT */
#if PPP_DATAINPUT
	NULL,
#endif /* PPP_DATAINPUT */
#if PRINTPKT_SUPPORT
	"IPCP",
	"IP",
#endif /* PRINTPKT_SUPPORT */
#if PPP_OPTIONS
	ipcp_option_list,
	ip_check_options,
#endif /* PPP_OPTIONS */
#if DEMAND_SUPPORT
	ip_demand_conf,
	ip_active_pkt
#endif /* DEMAND_SUPPORT */
};

static void ipcp_clear_addrs(ppp_pcb* pcb, u32_t ouraddr, u32_t hisaddr, u8_t replacedefaultroute);

/*
 * Lengths of configuration options.
 */
#define CILEN_VOID	2
#define CILEN_COMPRESS	4	/* min length for compression protocol opt. */
#define CILEN_VJ	6	/* length for RFC1332 Van-Jacobson opt. */
#define CILEN_ADDR	6	/* new-style single address option */
#define CILEN_ADDRS	10	/* old-style dual address option */


#define CODENAME(x)	((x) == CONFACK ? "ACK" : \
			 (x) == CONFNAK ? "NAK" : "REJ")

#if 0 /* UNUSED, already defined by lwIP */
/*
 * Make a string representation of a network IP address.
 */
char*
ip_ntoa(ipaddr)
u32_t ipaddr;
{
	static char b[64];

	slprintf(b, sizeof(b), "%I", ipaddr);
	return b;
}
#endif /* UNUSED, already defined by lwIP */

/*
 * Option parsing.
 */
#if PPP_OPTIONS
/*
 * setvjslots - set maximum number of connection slots for VJ compression
 */
static int
setvjslots(argv)
char** argv;
{
	int value;

	if(!int_option(*argv, &value))
		return 0;

	if(value < 2 || value > 16) {
		option_error("vj-max-slots value must be between 2 and 16");
		return 0;
	}

	ipcp_wantoptions [0].maxslotindex =
	    ipcp_allowoptions[0].maxslotindex = value - 1;
	slprintf(vj_value, sizeof(vj_value), "%d", value);
	return 1;
}

/*
 * setdnsaddr - set the dns address(es)
 */
static int
setdnsaddr(argv)
char** argv;
{
	u32_t dns;
	struct hostent* hp;

	dns = inet_addr(*argv);

	if(dns == (u32_t) -1) {
		if((hp = gethostbyname(*argv)) == NULL) {
			option_error("invalid address parameter '%s' for ms-dns option",
			             *argv);
			return 0;
		}

		dns = *(u32_t*)hp->h_addr;
	}

	/* We take the last 2 values given, the 2nd-last as the primary
	   and the last as the secondary.  If only one is given it
	   becomes both primary and secondary. */
	if(ipcp_allowoptions[0].dnsaddr[1] == 0)
		ipcp_allowoptions[0].dnsaddr[0] = dns;
	else
		ipcp_allowoptions[0].dnsaddr[0] = ipcp_allowoptions[0].dnsaddr[1];

	/* always set the secondary address value. */
	ipcp_allowoptions[0].dnsaddr[1] = dns;

	return (1);
}

/*
 * setwinsaddr - set the wins address(es)
 * This is primrarly used with the Samba package under UNIX or for pointing
 * the caller to the existing WINS server on a Windows NT platform.
 */
static int
setwinsaddr(argv)
char** argv;
{
	u32_t wins;
	struct hostent* hp;

	wins = inet_addr(*argv);

	if(wins == (u32_t) -1) {
		if((hp = gethostbyname(*argv)) == NULL) {
			option_error("invalid address parameter '%s' for ms-wins option",
			             *argv);
			return 0;
		}

		wins = *(u32_t*)hp->h_addr;
	}

	/* We take the last 2 values given, the 2nd-last as the primary
	   and the last as the secondary.  If only one is given it
	   becomes both primary and secondary. */
	if(ipcp_allowoptions[0].winsaddr[1] == 0)
		ipcp_allowoptions[0].winsaddr[0] = wins;
	else
		ipcp_allowoptions[0].winsaddr[0] = ipcp_allowoptions[0].winsaddr[1];

	/* always set the secondary address value. */
	ipcp_allowoptions[0].winsaddr[1] = wins;

	return (1);
}

/*
 * setipaddr - Set the IP address
 * If doit is 0, the call is to check whether this option is
 * potentially an IP address specification.
 * Not static so that plugins can call it to set the addresses
 */
int
setipaddr(arg, argv, doit)
char* arg;
char** argv;
int doit;
{
	struct hostent* hp;
	char* colon;
	u32_t local, remote;
	ipcp_options* wo = &ipcp_wantoptions[0];
	static int prio_local = 0, prio_remote = 0;

	/*
	 * IP address pair separated by ":".
	 */
	if((colon = strchr(arg, ':')) == NULL)
		return 0;

	if(!doit)
		return 1;

	/*
	 * If colon first character, then no local addr.
	 */
	if(colon != arg && option_priority >= prio_local) {
		*colon = '\0';

		if((local = inet_addr(arg)) == (u32_t) -1) {
			if((hp = gethostbyname(arg)) == NULL) {
				option_error("unknown host: %s", arg);
				return 0;
			}

			local = *(u32_t*)hp->h_addr;
		}

		if(bad_ip_adrs(local)) {
			option_error("bad local IP address %s", ip_ntoa(local));
			return 0;
		}

		if(local != 0)
			wo->ouraddr = local;

		*colon = ':';
		prio_local = option_priority;
	}

	/*
	 * If colon last character, then no remote addr.
	 */
	if(*++colon != '\0' && option_priority >= prio_remote) {
		if((remote = inet_addr(colon)) == (u32_t) -1) {
			if((hp = gethostbyname(colon)) == NULL) {
				option_error("unknown host: %s", colon);
				return 0;
			}

			remote = *(u32_t*)hp->h_addr;

			if(remote_name[0] == 0)
				strlcpy(remote_name, colon, sizeof(remote_name));
		}

		if(bad_ip_adrs(remote)) {
			option_error("bad remote IP address %s", ip_ntoa(remote));
			return 0;
		}

		if(remote != 0)
			wo->hisaddr = remote;

		prio_remote = option_priority;
	}

	return 1;
}

static void
printipaddr(opt, printer, arg)
option_t* opt;
void (*printer)(void*, char*, ...);
void* arg;
{
	ipcp_options* wo = &ipcp_wantoptions[0];

	if(wo->ouraddr != 0)
		printer(arg, "%I", wo->ouraddr);

	printer(arg, ":");

	if(wo->hisaddr != 0)
		printer(arg, "%I", wo->hisaddr);
}

/*
 * setnetmask - set the netmask to be used on the interface.
 */
static int
setnetmask(argv)
char** argv;
{
	u32_t mask;
	int n;
	char* p;

	/*
	 * Unfortunately, if we use inet_addr, we can't tell whether
	 * a result of all 1s is an error or a valid 255.255.255.255.
	 */
	p = *argv;
	n = parse_dotted_ip(p, &mask);

	mask = lwip_htonl(mask);

	if(n == 0 || p[n] != 0 || (netmask & ~mask) != 0) {
		option_error("invalid netmask value '%s'", *argv);
		return 0;
	}

	netmask = mask;
	slprintf(netmask_str, sizeof(netmask_str), "%I", mask);

	return (1);
}

int
parse_dotted_ip(p, vp)
char* p;
u32_t* vp;
{
	int n;
	u32_t v, b;
	char* endp, *p0 = p;

	v = 0;

	for(n = 3;; --n) {
		b = strtoul(p, &endp, 0);

		if(endp == p)
			return 0;

		if(b > 255) {
			if(n < 3)
				return 0;

			/* accept e.g. 0xffffff00 */
			*vp = b;
			return endp - p0;
		}

		v |= b << (n * 8);
		p = endp;

		if(n == 0)
			break;

		if(*p != '.')
			return 0;

		++p;
	}

	*vp = v;
	return p - p0;
}
#endif /* PPP_OPTIONS */

/*
 * ipcp_init - Initialize IPCP.
 */
static void ipcp_init(ppp_pcb* pcb)
{
	fsm* f = &pcb->ipcp_fsm;

	ipcp_options* wo = &pcb->ipcp_wantoptions;
	ipcp_options* ao = &pcb->ipcp_allowoptions;

	f->pcb = pcb;
	f->protocol = PPP_IPCP;
	f->callbacks = &ipcp_callbacks;
	fsm_init(f);

	/*
	 * Some 3G modems use repeated IPCP NAKs as a way of stalling
	 * until they can contact a server on the network, so we increase
	 * the default number of NAKs we accept before we start treating
	 * them as rejects.
	 */
	f->maxnakloops = 100;

#if 0 /* Not necessary, everything is cleared in ppp_new() */
	memset(wo, 0, sizeof(*wo));
	memset(ao, 0, sizeof(*ao));
#endif /* 0 */

	wo->neg_addr = wo->old_addrs = 1;
#if VJ_SUPPORT
	wo->neg_vj = 1;
	wo->vj_protocol = IPCP_VJ_COMP;
	wo->maxslotindex = MAX_STATES - 1; /* really max index */
	wo->cflag = 1;
#endif /* VJ_SUPPORT */

#if 0 /* UNUSED */
	/* wanting default route by default */
	wo->default_route = 1;
#endif /* UNUSED */

	ao->neg_addr = ao->old_addrs = 1;
#if VJ_SUPPORT
	/* max slots and slot-id compression are currently hardwired in */
	/* ppp_if.c to 16 and 1, this needs to be changed (among other */
	/* things) gmc */

	ao->neg_vj = 1;
	ao->maxslotindex = MAX_STATES - 1;
	ao->cflag = 1;
#endif /* #if VJ_SUPPORT */

#if 0 /* UNUSED */
	/*
	 * XXX These control whether the user may use the proxyarp
	 * and defaultroute options.
	 */
	ao->proxy_arp = 1;
	ao->default_route = 1;
#endif /* UNUSED */
}


/*
 * ipcp_open - IPCP is allowed to come up.
 */
static void ipcp_open(ppp_pcb* pcb)
{
	fsm* f = &pcb->ipcp_fsm;
	fsm_open(f);
	pcb->ipcp_is_open = 1;
}


/*
 * ipcp_close - Take IPCP down.
 */
static void ipcp_close(ppp_pcb* pcb, const char* reason)
{
	fsm* f = &pcb->ipcp_fsm;
	fsm_close(f, reason);
}


/*
 * ipcp_lowerup - The lower layer is up.
 */
static void ipcp_lowerup(ppp_pcb* pcb)
{
	fsm* f = &pcb->ipcp_fsm;
	fsm_lowerup(f);
}


/*
 * ipcp_lowerdown - The lower layer is down.
 */
static void ipcp_lowerdown(ppp_pcb* pcb)
{
	fsm* f = &pcb->ipcp_fsm;
	fsm_lowerdown(f);
}


/*
 * ipcp_input - Input IPCP packet.
 */
static void ipcp_input(ppp_pcb* pcb, u_char* p, int len)
{
	fsm* f = &pcb->ipcp_fsm;
	fsm_input(f, p, len);
}


/*
 * ipcp_protrej - A Protocol-Reject was received for IPCP.
 *
 * Pretend the lower layer went down, so we shut up.
 */
static void ipcp_protrej(ppp_pcb* pcb)
{
	fsm* f = &pcb->ipcp_fsm;
	fsm_lowerdown(f);
}


/*
 * ipcp_resetci - Reset our CI.
 * Called by fsm_sconfreq, Send Configure Request.
 */
static void ipcp_resetci(fsm* f)
{
	ppp_pcb* pcb = f->pcb;
	ipcp_options* wo = &pcb->ipcp_wantoptions;
	ipcp_options* go = &pcb->ipcp_gotoptions;
	ipcp_options* ao = &pcb->ipcp_allowoptions;

	wo->req_addr = (wo->neg_addr || wo->old_addrs) &&
	               (ao->neg_addr || ao->old_addrs);

	if(wo->ouraddr == 0)
		wo->accept_local = 1;

	if(wo->hisaddr == 0)
		wo->accept_remote = 1;

#if LWIP_DNS
	wo->req_dns1 = wo->req_dns2 = pcb->settings.usepeerdns;	/* Request DNS addresses from the peer */
#endif /* LWIP_DNS */
	*go = *wo;

	if(!pcb->ask_for_local)
		go->ouraddr = 0;

#if 0 /* UNUSED */

	if(ip_choose_hook) {
		ip_choose_hook(&wo->hisaddr);

		if(wo->hisaddr) {
			wo->accept_remote = 0;
		}
	}

#endif /* UNUSED */
	BZERO(&pcb->ipcp_hisoptions, sizeof(ipcp_options));
}


/*
 * ipcp_cilen - Return length of our CI.
 * Called by fsm_sconfreq, Send Configure Request.
 */
static int ipcp_cilen(fsm* f)
{
	ppp_pcb* pcb = f->pcb;
	ipcp_options* go = &pcb->ipcp_gotoptions;
#if VJ_SUPPORT
	ipcp_options* wo = &pcb->ipcp_wantoptions;
#endif /* VJ_SUPPORT */
	ipcp_options* ho = &pcb->ipcp_hisoptions;

#define LENCIADDRS(neg)		(neg ? CILEN_ADDRS : 0)
#if VJ_SUPPORT
#define LENCIVJ(neg, old)	(neg ? (old? CILEN_COMPRESS : CILEN_VJ) : 0)
#endif /* VJ_SUPPORT */
#define LENCIADDR(neg)		(neg ? CILEN_ADDR : 0)
#if LWIP_DNS
#define LENCIDNS(neg)		LENCIADDR(neg)
#endif /* LWIP_DNS */
#if 0 /* UNUSED - WINS */
#define LENCIWINS(neg)		LENCIADDR(neg)
#endif /* UNUSED - WINS */

	/*
	 * First see if we want to change our options to the old
	 * forms because we have received old forms from the peer.
	 */
	if(go->neg_addr && go->old_addrs && !ho->neg_addr && ho->old_addrs)
		go->neg_addr = 0;

#if VJ_SUPPORT

	if(wo->neg_vj && !go->neg_vj && !go->old_vj) {
		/* try an older style of VJ negotiation */
		/* use the old style only if the peer did */
		if(ho->neg_vj && ho->old_vj) {
			go->neg_vj = 1;
			go->old_vj = 1;
			go->vj_protocol = ho->vj_protocol;
		}
	}

#endif /* VJ_SUPPORT */

	return (LENCIADDRS(!go->neg_addr && go->old_addrs) +
#if VJ_SUPPORT
	        LENCIVJ(go->neg_vj, go->old_vj) +
#endif /* VJ_SUPPORT */
	        LENCIADDR(go->neg_addr) +
#if LWIP_DNS
	        LENCIDNS(go->req_dns1) +
	        LENCIDNS(go->req_dns2) +
#endif /* LWIP_DNS */
#if 0 /* UNUSED - WINS */
	        LENCIWINS(go->winsaddr[0]) +
	        LENCIWINS(go->winsaddr[1]) +
#endif /* UNUSED - WINS */
	        0);
}


/*
 * ipcp_addci - Add our desired CIs to a packet.
 * Called by fsm_sconfreq, Send Configure Request.
 */
static void ipcp_addci(fsm* f, u_char* ucp, int* lenp)
{
	ppp_pcb* pcb = f->pcb;
	ipcp_options* go = &pcb->ipcp_gotoptions;
	int len = *lenp;

#define ADDCIADDRS(opt, neg, val1, val2) \
    if (neg) { \
	if (len >= CILEN_ADDRS) { \
	    u32_t l; \
	    PUTCHAR(opt, ucp); \
	    PUTCHAR(CILEN_ADDRS, ucp); \
	    l = lwip_ntohl(val1); \
	    PUTLONG(l, ucp); \
	    l = lwip_ntohl(val2); \
	    PUTLONG(l, ucp); \
	    len -= CILEN_ADDRS; \
	} else \
	    go->old_addrs = 0; \
    }

#if VJ_SUPPORT
#define ADDCIVJ(opt, neg, val, old, maxslotindex, cflag) \
    if (neg) { \
	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
	if (len >= vjlen) { \
	    PUTCHAR(opt, ucp); \
	    PUTCHAR(vjlen, ucp); \
	    PUTSHORT(val, ucp); \
	    if (!old) { \
		PUTCHAR(maxslotindex, ucp); \
		PUTCHAR(cflag, ucp); \
	    } \
	    len -= vjlen; \
	} else \
	    neg = 0; \
    }
#endif /* VJ_SUPPORT */

#define ADDCIADDR(opt, neg, val) \
    if (neg) { \
	if (len >= CILEN_ADDR) { \
	    u32_t l; \
	    PUTCHAR(opt, ucp); \
	    PUTCHAR(CILEN_ADDR, ucp); \
	    l = lwip_ntohl(val); \
	    PUTLONG(l, ucp); \
	    len -= CILEN_ADDR; \
	} else \
	    neg = 0; \
    }

#if LWIP_DNS
#define ADDCIDNS(opt, neg, addr) \
    if (neg) { \
	if (len >= CILEN_ADDR) { \
	    u32_t l; \
	    PUTCHAR(opt, ucp); \
	    PUTCHAR(CILEN_ADDR, ucp); \
	    l = lwip_ntohl(addr); \
	    PUTLONG(l, ucp); \
	    len -= CILEN_ADDR; \
	} else \
	    neg = 0; \
    }
#endif /* LWIP_DNS */

#if 0 /* UNUSED - WINS */
#define ADDCIWINS(opt, addr) \
    if (addr) { \
	if (len >= CILEN_ADDR) { \
	    u32_t l; \
	    PUTCHAR(opt, ucp); \
	    PUTCHAR(CILEN_ADDR, ucp); \
	    l = lwip_ntohl(addr); \
	    PUTLONG(l, ucp); \
	    len -= CILEN_ADDR; \
	} else \
	    addr = 0; \
    }
#endif /* UNUSED - WINS */

	ADDCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
	           go->hisaddr);

#if VJ_SUPPORT
	ADDCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
	        go->maxslotindex, go->cflag);
#endif /* VJ_SUPPORT */

	ADDCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);

#if LWIP_DNS
	ADDCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);

	ADDCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
#endif /* LWIP_DNS */

#if 0 /* UNUSED - WINS */
	ADDCIWINS(CI_MS_WINS1, go->winsaddr[0]);

	ADDCIWINS(CI_MS_WINS2, go->winsaddr[1]);
#endif /* UNUSED - WINS */

	*lenp -= len;
}


/*
 * ipcp_ackci - Ack our CIs.
 * Called by fsm_rconfack, Receive Configure ACK.
 *
 * Returns:
 *	0 - Ack was bad.
 *	1 - Ack was good.
 */
static int ipcp_ackci(fsm* f, u_char* p, int len)
{
	ppp_pcb* pcb = f->pcb;
	ipcp_options* go = &pcb->ipcp_gotoptions;
	u_short cilen, citype;
	u32_t cilong;
#if VJ_SUPPORT
	u_short cishort;
	u_char cimaxslotindex, cicflag;
#endif /* VJ_SUPPORT */

	/*
	 * CIs must be in exactly the same order that we sent...
	 * Check packet length and CI length at each step.
	 * If we find any deviations, then this packet is bad.
	 */

#define ACKCIADDRS(opt, neg, val1, val2) \
    if (neg) { \
	u32_t l; \
	if ((len -= CILEN_ADDRS) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_ADDRS || \
	    citype != opt) \
	    goto bad; \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	if (val1 != cilong) \
	    goto bad; \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	if (val2 != cilong) \
	    goto bad; \
    }

#if VJ_SUPPORT
#define ACKCIVJ(opt, neg, val, old, maxslotindex, cflag) \
    if (neg) { \
	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
	if ((len -= vjlen) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != vjlen || \
	    citype != opt)  \
	    goto bad; \
	GETSHORT(cishort, p); \
	if (cishort != val) \
	    goto bad; \
	if (!old) { \
	    GETCHAR(cimaxslotindex, p); \
	    if (cimaxslotindex != maxslotindex) \
		goto bad; \
	    GETCHAR(cicflag, p); \
	    if (cicflag != cflag) \
		goto bad; \
	} \
    }
#endif /* VJ_SUPPORT */

#define ACKCIADDR(opt, neg, val) \
    if (neg) { \
	u32_t l; \
	if ((len -= CILEN_ADDR) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_ADDR || \
	    citype != opt) \
	    goto bad; \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	if (val != cilong) \
	    goto bad; \
    }

#if LWIP_DNS
#define ACKCIDNS(opt, neg, addr) \
    if (neg) { \
	u32_t l; \
	if ((len -= CILEN_ADDR) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_ADDR || citype != opt) \
	    goto bad; \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	if (addr != cilong) \
	    goto bad; \
    }
#endif /* LWIP_DNS */

#if 0 /* UNUSED - WINS */
#define ACKCIWINS(opt, addr) \
    if (addr) { \
	u32_t l; \
	if ((len -= CILEN_ADDR) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_ADDR || citype != opt) \
	    goto bad; \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	if (addr != cilong) \
	    goto bad; \
    }
#endif /* UNUSED - WINS */

	ACKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
	           go->hisaddr);

#if VJ_SUPPORT
	ACKCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
	        go->maxslotindex, go->cflag);
#endif /* VJ_SUPPORT */

	ACKCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);

#if LWIP_DNS
	ACKCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);

	ACKCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
#endif /* LWIP_DNS */

#if 0 /* UNUSED - WINS */
	ACKCIWINS(CI_MS_WINS1, go->winsaddr[0]);

	ACKCIWINS(CI_MS_WINS2, go->winsaddr[1]);
#endif /* UNUSED - WINS */

	/*
	 * If there are any remaining CIs, then this packet is bad.
	 */
	if(len != 0)
		goto bad;

	return (1);

bad:
	IPCPDEBUG(("ipcp_ackci: received bad Ack!"));
	return (0);
}

/*
 * ipcp_nakci - Peer has sent a NAK for some of our CIs.
 * This should not modify any state if the Nak is bad
 * or if IPCP is in the OPENED state.
 * Calback from fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
 *
 * Returns:
 *	0 - Nak was bad.
 *	1 - Nak was good.
 */
static int ipcp_nakci(fsm* f, u_char* p, int len, int treat_as_reject)
{
	ppp_pcb* pcb = f->pcb;
	ipcp_options* go = &pcb->ipcp_gotoptions;
	u_char citype, cilen, *next;
#if VJ_SUPPORT
	u_char cimaxslotindex, cicflag;
	u_short cishort;
#endif /* VJ_SUPPORT */
	u32_t ciaddr1, ciaddr2, l;
#if LWIP_DNS
	u32_t cidnsaddr;
#endif /* LWIP_DNS */
	ipcp_options no;		/* options we've seen Naks for */
	ipcp_options try_;		/* options to request next time */

	BZERO(&no, sizeof(no));
	try_ = *go;

	/*
	 * Any Nak'd CIs must be in exactly the same order that we sent.
	 * Check packet length and CI length at each step.
	 * If we find any deviations, then this packet is bad.
	 */
#define NAKCIADDRS(opt, neg, code) \
    if ((neg) && \
	(cilen = p[1]) == CILEN_ADDRS && \
	len >= cilen && \
	p[0] == opt) { \
	len -= cilen; \
	INCPTR(2, p); \
	GETLONG(l, p); \
	ciaddr1 = lwip_htonl(l); \
	GETLONG(l, p); \
	ciaddr2 = lwip_htonl(l); \
	no.old_addrs = 1; \
	code \
    }

#if VJ_SUPPORT
#define NAKCIVJ(opt, neg, code) \
    if (go->neg && \
	((cilen = p[1]) == CILEN_COMPRESS || cilen == CILEN_VJ) && \
	len >= cilen && \
	p[0] == opt) { \
	len -= cilen; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	no.neg = 1; \
        code \
    }
#endif /* VJ_SUPPORT */

#define NAKCIADDR(opt, neg, code) \
    if (go->neg && \
	(cilen = p[1]) == CILEN_ADDR && \
	len >= cilen && \
	p[0] == opt) { \
	len -= cilen; \
	INCPTR(2, p); \
	GETLONG(l, p); \
	ciaddr1 = lwip_htonl(l); \
	no.neg = 1; \
	code \
    }

#if LWIP_DNS
#define NAKCIDNS(opt, neg, code) \
    if (go->neg && \
	((cilen = p[1]) == CILEN_ADDR) && \
	len >= cilen && \
	p[0] == opt) { \
	len -= cilen; \
	INCPTR(2, p); \
	GETLONG(l, p); \
	cidnsaddr = lwip_htonl(l); \
	no.neg = 1; \
	code \
    }
#endif /* LWIP_DNS */

	/*
	 * Accept the peer's idea of {our,his} address, if different
	 * from our idea, only if the accept_{local,remote} flag is set.
	 */
	NAKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,

	if(treat_as_reject) {
	try_.old_addrs = 0;
} else {
	if(go->accept_local && ciaddr1) {
			/* take his idea of our address */
			try_.ouraddr = ciaddr1;
		}

		if(go->accept_remote && ciaddr2) {
			/* take his idea of his address */
			try_.hisaddr = ciaddr2;
		}
	}
	          );

#if VJ_SUPPORT
	/*
	 * Accept the peer's value of maxslotindex provided that it
	 * is less than what we asked for.  Turn off slot-ID compression
	 * if the peer wants.  Send old-style compress-type option if
	 * the peer wants.
	 */
	NAKCIVJ(CI_COMPRESSTYPE, neg_vj,

	if(treat_as_reject) {
	try_.neg_vj = 0;
} else if(cilen == CILEN_VJ) {
	GETCHAR(cimaxslotindex, p);
		GETCHAR(cicflag, p);

		if(cishort == IPCP_VJ_COMP) {
			try_.old_vj = 0;

			if(cimaxslotindex < go->maxslotindex)
				try_.maxslotindex = cimaxslotindex;

			if(!cicflag)
				try_.cflag = 0;
		} else {
			try_.neg_vj = 0;
		}
	} else {
		if(cishort == IPCP_VJ_COMP || cishort == IPCP_VJ_COMP_OLD) {
			try_.old_vj = 1;
			try_.vj_protocol = cishort;
		} else {
			try_.neg_vj = 0;
		}
	}
	       );
#endif /* VJ_SUPPORT */

	NAKCIADDR(CI_ADDR, neg_addr,

	if(treat_as_reject) {
	try_.neg_addr = 0;
	try_.old_addrs = 0;
} else if(go->accept_local && ciaddr1) {
	/* take his idea of our address */
	try_.ouraddr = ciaddr1;
}
         );

#if LWIP_DNS
	NAKCIDNS(CI_MS_DNS1, req_dns1,

	if(treat_as_reject) {
	try_.req_dns1 = 0;
} else {
	try_.dnsaddr[0] = cidnsaddr;
	}
	        );

	NAKCIDNS(CI_MS_DNS2, req_dns2,

	if(treat_as_reject) {
	try_.req_dns2 = 0;
} else {
	try_.dnsaddr[1] = cidnsaddr;
	}
	        );
#endif /* #if LWIP_DNS */

	/*
	 * There may be remaining CIs, if the peer is requesting negotiation
	 * on an option that we didn't include in our request packet.
	 * If they want to negotiate about IP addresses, we comply.
	 * If they want us to ask for compression, we refuse.
	 * If they want us to ask for ms-dns, we do that, since some
	 * peers get huffy if we don't.
	 */
	while(len >= CILEN_VOID) {
		GETCHAR(citype, p);
		GETCHAR(cilen, p);

		if(cilen < CILEN_VOID || (len -= cilen) < 0)
			goto bad;

		next = p + cilen - 2;

		switch(citype) {
#if VJ_SUPPORT

			case CI_COMPRESSTYPE:
				if(go->neg_vj || no.neg_vj ||
				        (cilen != CILEN_VJ && cilen != CILEN_COMPRESS))
					goto bad;

				no.neg_vj = 1;
				break;
#endif /* VJ_SUPPORT */

			case CI_ADDRS:
				if((!go->neg_addr && go->old_addrs) || no.old_addrs
				        || cilen != CILEN_ADDRS)
					goto bad;

				try_.neg_addr = 0;
				GETLONG(l, p);
				ciaddr1 = lwip_htonl(l);

				if(ciaddr1 && go->accept_local)
					try_.ouraddr = ciaddr1;

				GETLONG(l, p);
				ciaddr2 = lwip_htonl(l);

				if(ciaddr2 && go->accept_remote)
					try_.hisaddr = ciaddr2;

				no.old_addrs = 1;
				break;

			case CI_ADDR:
				if(go->neg_addr || no.neg_addr || cilen != CILEN_ADDR)
					goto bad;

				try_.old_addrs = 0;
				GETLONG(l, p);
				ciaddr1 = lwip_htonl(l);

				if(ciaddr1 && go->accept_local)
					try_.ouraddr = ciaddr1;

				if(try_.ouraddr != 0)
					try_.neg_addr = 1;

				no.neg_addr = 1;
				break;
#if LWIP_DNS

			case CI_MS_DNS1:
				if(go->req_dns1 || no.req_dns1 || cilen != CILEN_ADDR)
					goto bad;

				GETLONG(l, p);
				try_.dnsaddr[0] = lwip_htonl(l);
				try_.req_dns1 = 1;
				no.req_dns1 = 1;
				break;

			case CI_MS_DNS2:
				if(go->req_dns2 || no.req_dns2 || cilen != CILEN_ADDR)
					goto bad;

				GETLONG(l, p);
				try_.dnsaddr[1] = lwip_htonl(l);
				try_.req_dns2 = 1;
				no.req_dns2 = 1;
				break;
#endif /* LWIP_DNS */
#if 0 /* UNUSED - WINS */

			case CI_MS_WINS1:
			case CI_MS_WINS2:
				if(cilen != CILEN_ADDR)
					goto bad;

				GETLONG(l, p);
				ciaddr1 = lwip_htonl(l);

				if(ciaddr1)
					try_.winsaddr[citype == CI_MS_WINS2] = ciaddr1;

				break;
#endif /* UNUSED - WINS */

			default:
				break;
		}

		p = next;
	}

	/*
	 * OK, the Nak is good.  Now we can update state.
	 * If there are any remaining options, we ignore them.
	 */
	if(f->state != PPP_FSM_OPENED)
		*go = try_;

	return 1;

bad:
	IPCPDEBUG(("ipcp_nakci: received bad Nak!"));
	return 0;
}


/*
 * ipcp_rejci - Reject some of our CIs.
 * Callback from fsm_rconfnakrej.
 */
static int ipcp_rejci(fsm* f, u_char* p, int len)
{
	ppp_pcb* pcb = f->pcb;
	ipcp_options* go = &pcb->ipcp_gotoptions;
	u_char cilen;
#if VJ_SUPPORT
	u_char cimaxslotindex, ciflag;
	u_short cishort;
#endif /* VJ_SUPPORT */
	u32_t cilong;
	ipcp_options try_;		/* options to request next time */

	try_ = *go;
	/*
	 * Any Rejected CIs must be in exactly the same order that we sent.
	 * Check packet length and CI length at each step.
	 * If we find any deviations, then this packet is bad.
	 */
#define REJCIADDRS(opt, neg, val1, val2) \
    if ((neg) && \
	(cilen = p[1]) == CILEN_ADDRS && \
	len >= cilen && \
	p[0] == opt) { \
	u32_t l; \
	len -= cilen; \
	INCPTR(2, p); \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	/* Check rejected value. */ \
	if (cilong != val1) \
	    goto bad; \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	/* Check rejected value. */ \
	if (cilong != val2) \
	    goto bad; \
	try_.old_addrs = 0; \
    }

#if VJ_SUPPORT
#define REJCIVJ(opt, neg, val, old, maxslot, cflag) \
    if (go->neg && \
	p[1] == (old? CILEN_COMPRESS : CILEN_VJ) && \
	len >= p[1] && \
	p[0] == opt) { \
	len -= p[1]; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	/* Check rejected value. */  \
	if (cishort != val) \
	    goto bad; \
	if (!old) { \
	   GETCHAR(cimaxslotindex, p); \
	   if (cimaxslotindex != maxslot) \
	     goto bad; \
	   GETCHAR(ciflag, p); \
	   if (ciflag != cflag) \
	     goto bad; \
        } \
	try_.neg = 0; \
     }
#endif /* VJ_SUPPORT */

#define REJCIADDR(opt, neg, val) \
    if (go->neg && \
	(cilen = p[1]) == CILEN_ADDR && \
	len >= cilen && \
	p[0] == opt) { \
	u32_t l; \
	len -= cilen; \
	INCPTR(2, p); \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	/* Check rejected value. */ \
	if (cilong != val) \
	    goto bad; \
	try_.neg = 0; \
    }

#if LWIP_DNS
#define REJCIDNS(opt, neg, dnsaddr) \
    if (go->neg && \
	((cilen = p[1]) == CILEN_ADDR) && \
	len >= cilen && \
	p[0] == opt) { \
	u32_t l; \
	len -= cilen; \
	INCPTR(2, p); \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	/* Check rejected value. */ \
	if (cilong != dnsaddr) \
	    goto bad; \
	try_.neg = 0; \
    }
#endif /* LWIP_DNS */

#if 0 /* UNUSED - WINS */
#define REJCIWINS(opt, addr) \
    if (addr && \
	((cilen = p[1]) == CILEN_ADDR) && \
	len >= cilen && \
	p[0] == opt) { \
	u32_t l; \
	len -= cilen; \
	INCPTR(2, p); \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	/* Check rejected value. */ \
	if (cilong != addr) \
	    goto bad; \
	try_.winsaddr[opt == CI_MS_WINS2] = 0; \
    }
#endif /* UNUSED - WINS */

	REJCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
	           go->ouraddr, go->hisaddr);

#if VJ_SUPPORT
	REJCIVJ(CI_COMPRESSTYPE, neg_vj, go->vj_protocol, go->old_vj,
	        go->maxslotindex, go->cflag);
#endif /* VJ_SUPPORT */

	REJCIADDR(CI_ADDR, neg_addr, go->ouraddr);

#if LWIP_DNS
	REJCIDNS(CI_MS_DNS1, req_dns1, go->dnsaddr[0]);

	REJCIDNS(CI_MS_DNS2, req_dns2, go->dnsaddr[1]);
#endif /* LWIP_DNS */

#if 0 /* UNUSED - WINS */
	REJCIWINS(CI_MS_WINS1, go->winsaddr[0]);

	REJCIWINS(CI_MS_WINS2, go->winsaddr[1]);
#endif /* UNUSED - WINS */

	/*
	 * If there are any remaining CIs, then this packet is bad.
	 */
	if(len != 0)
		goto bad;

	/*
	 * Now we can update state.
	 */
	if(f->state != PPP_FSM_OPENED)
		*go = try_;

	return 1;

bad:
	IPCPDEBUG(("ipcp_rejci: received bad Reject!"));
	return 0;
}


/*
 * ipcp_reqci - Check the peer's requested CIs and send appropriate response.
 * Callback from fsm_rconfreq, Receive Configure Request
 *
 * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified
 * appropriately.  If reject_if_disagree is non-zero, doesn't return
 * CONFNAK; returns CONFREJ if it can't return CONFACK.
 *
 * inp = Requested CIs
 * len = Length of requested CIs
 */
static int ipcp_reqci(fsm* f, u_char* inp, int* len, int reject_if_disagree)
{
	ppp_pcb* pcb = f->pcb;
	ipcp_options* wo = &pcb->ipcp_wantoptions;
	ipcp_options* ho = &pcb->ipcp_hisoptions;
	ipcp_options* ao = &pcb->ipcp_allowoptions;
	u_char* cip, *next;		/* Pointer to current and next CIs */
	u_short cilen, citype;	/* Parsed len, type */
#if VJ_SUPPORT
	u_short cishort;		/* Parsed short value */
#endif /* VJ_SUPPORT */
	u32_t tl, ciaddr1, ciaddr2;/* Parsed address values */
	int rc = CONFACK;		/* Final packet return code */
	int orc;			/* Individual option return code */
	u_char* p;			/* Pointer to next char to parse */
	u_char* ucp = inp;		/* Pointer to current output char */
	int l = *len;		/* Length left */
#if VJ_SUPPORT
	u_char maxslotindex, cflag;
#endif /* VJ_SUPPORT */
#if LWIP_DNS
	int d;
#endif /* LWIP_DNS */

	/*
	 * Reset all his options.
	 */
	BZERO(ho, sizeof(*ho));

	/*
	 * Process all his options.
	 */
	next = inp;

	while(l) {
		orc = CONFACK;			/* Assume success */
		cip = p = next;			/* Remember begining of CI */

		if(l < 2 ||			/* Not enough data for CI header or */
		        p[1] < 2 ||			/*  CI length too small or */
		        p[1] > l) {			/*  CI length too big? */
			IPCPDEBUG(("ipcp_reqci: bad CI length!"));
			orc = CONFREJ;		/* Reject bad CI */
			cilen = l;			/* Reject till end of packet */
			l = 0;			/* Don't loop again */
			goto endswitch;
		}

		GETCHAR(citype, p);		/* Parse CI type */
		GETCHAR(cilen, p);		/* Parse CI length */
		l -= cilen;			/* Adjust remaining length */
		next += cilen;			/* Step to next CI */

		switch(citype) {		/* Check CI type */
			case CI_ADDRS:
				if(!ao->old_addrs || ho->neg_addr ||
				        cilen != CILEN_ADDRS) {	/* Check CI length */
					orc = CONFREJ;		/* Reject CI */
					break;
				}

				/*
				 * If he has no address, or if we both have his address but
				 * disagree about it, then NAK it with our idea.
				 * In particular, if we don't know his address, but he does,
				 * then accept it.
				 */
				GETLONG(tl, p);		/* Parse source address (his) */
				ciaddr1 = lwip_htonl(tl);

				if(ciaddr1 != wo->hisaddr
				        && (ciaddr1 == 0 || !wo->accept_remote)) {
					orc = CONFNAK;

					if(!reject_if_disagree) {
						DECPTR(sizeof(u32_t), p);
						tl = lwip_ntohl(wo->hisaddr);
						PUTLONG(tl, p);
					}
				} else if(ciaddr1 == 0 && wo->hisaddr == 0) {
					/*
					 * If neither we nor he knows his address, reject the option.
					 */
					orc = CONFREJ;
					wo->req_addr = 0;	/* don't NAK with 0.0.0.0 later */
					break;
				}

				/*
				 * If he doesn't know our address, or if we both have our address
				 * but disagree about it, then NAK it with our idea.
				 */
				GETLONG(tl, p);		/* Parse desination address (ours) */
				ciaddr2 = lwip_htonl(tl);

				if(ciaddr2 != wo->ouraddr) {
					if(ciaddr2 == 0 || !wo->accept_local) {
						orc = CONFNAK;

						if(!reject_if_disagree) {
							DECPTR(sizeof(u32_t), p);
							tl = lwip_ntohl(wo->ouraddr);
							PUTLONG(tl, p);
						}
					} else {
						wo->ouraddr = ciaddr2;	/* accept peer's idea */
					}
				}

				ho->old_addrs = 1;
				ho->hisaddr = ciaddr1;
				ho->ouraddr = ciaddr2;
				break;

			case CI_ADDR:
				if(!ao->neg_addr || ho->old_addrs ||
				        cilen != CILEN_ADDR) {	/* Check CI length */
					orc = CONFREJ;		/* Reject CI */
					break;
				}

				/*
				 * If he has no address, or if we both have his address but
				 * disagree about it, then NAK it with our idea.
				 * In particular, if we don't know his address, but he does,
				 * then accept it.
				 */
				GETLONG(tl, p);	/* Parse source address (his) */
				ciaddr1 = lwip_htonl(tl);

				if(ciaddr1 != wo->hisaddr
				        && (ciaddr1 == 0 || !wo->accept_remote)) {
					orc = CONFNAK;

					if(!reject_if_disagree) {
						DECPTR(sizeof(u32_t), p);
						tl = lwip_ntohl(wo->hisaddr);
						PUTLONG(tl, p);
					}
				} else if(ciaddr1 == 0 && wo->hisaddr == 0) {
					/*
					 * Don't ACK an address of 0.0.0.0 - reject it instead.
					 */
					orc = CONFREJ;
					wo->req_addr = 0;	/* don't NAK with 0.0.0.0 later */
					break;
				}

				ho->neg_addr = 1;
				ho->hisaddr = ciaddr1;
				break;

#if LWIP_DNS

			case CI_MS_DNS1:
			case CI_MS_DNS2:
				/* Microsoft primary or secondary DNS request */
				d = citype == CI_MS_DNS2;

				/* If we do not have a DNS address then we cannot send it */
				if(ao->dnsaddr[d] == 0 ||
				        cilen != CILEN_ADDR) {	/* Check CI length */
					orc = CONFREJ;		/* Reject CI */
					break;
				}

				GETLONG(tl, p);

				if(lwip_htonl(tl) != ao->dnsaddr[d]) {
					DECPTR(sizeof(u32_t), p);
					tl = lwip_ntohl(ao->dnsaddr[d]);
					PUTLONG(tl, p);
					orc = CONFNAK;
				}

				break;
#endif /* LWIP_DNS */

#if 0 /* UNUSED - WINS */

			case CI_MS_WINS1:
			case CI_MS_WINS2:
				/* Microsoft primary or secondary WINS request */
				d = citype == CI_MS_WINS2;

				/* If we do not have a DNS address then we cannot send it */
				if(ao->winsaddr[d] == 0 ||
				        cilen != CILEN_ADDR) {	/* Check CI length */
					orc = CONFREJ;		/* Reject CI */
					break;
				}

				GETLONG(tl, p);

				if(lwip_htonl(tl) != ao->winsaddr[d]) {
					DECPTR(sizeof(u32_t), p);
					tl = lwip_ntohl(ao->winsaddr[d]);
					PUTLONG(tl, p);
					orc = CONFNAK;
				}

				break;
#endif /* UNUSED - WINS */

#if VJ_SUPPORT

			case CI_COMPRESSTYPE:
				if(!ao->neg_vj ||
				        (cilen != CILEN_VJ && cilen != CILEN_COMPRESS)) {
					orc = CONFREJ;
					break;
				}

				GETSHORT(cishort, p);

				if(!(cishort == IPCP_VJ_COMP ||
				        (cishort == IPCP_VJ_COMP_OLD && cilen == CILEN_COMPRESS))) {
					orc = CONFREJ;
					break;
				}

				ho->neg_vj = 1;
				ho->vj_protocol = cishort;

				if(cilen == CILEN_VJ) {
					GETCHAR(maxslotindex, p);

					if(maxslotindex > ao->maxslotindex) {
						orc = CONFNAK;

						if(!reject_if_disagree) {
							DECPTR(1, p);
							PUTCHAR(ao->maxslotindex, p);
						}
					}

					GETCHAR(cflag, p);

					if(cflag && !ao->cflag) {
						orc = CONFNAK;

						if(!reject_if_disagree) {
							DECPTR(1, p);
							PUTCHAR(wo->cflag, p);
						}
					}

					ho->maxslotindex = maxslotindex;
					ho->cflag = cflag;
				} else {
					ho->old_vj = 1;
					ho->maxslotindex = MAX_STATES - 1;
					ho->cflag = 1;
				}

				break;
#endif /* VJ_SUPPORT */

			default:
				orc = CONFREJ;
				break;
		}

endswitch:

		if(orc == CONFACK &&		/* Good CI */
		        rc != CONFACK)		/*  but prior CI wasnt? */
			continue;			/* Don't send this one */

		if(orc == CONFNAK) {		/* Nak this CI? */
			if(reject_if_disagree)	/* Getting fed up with sending NAKs? */
				orc = CONFREJ;		/* Get tough if so */
			else {
				if(rc == CONFREJ)	/* Rejecting prior CI? */
					continue;		/* Don't send this one */

				if(rc == CONFACK) {	/* Ack'd all prior CIs? */
					rc = CONFNAK;	/* Not anymore... */
					ucp = inp;		/* Backup */
				}
			}
		}

		if(orc == CONFREJ &&		/* Reject this CI */
		        rc != CONFREJ) {		/*  but no prior ones? */
			rc = CONFREJ;
			ucp = inp;			/* Backup */
		}

		/* Need to move CI? */
		if(ucp != cip)
			MEMCPY(ucp, cip, cilen);	/* Move it */

		/* Update output pointer */
		INCPTR(cilen, ucp);
	}

	/*
	 * If we aren't rejecting this packet, and we want to negotiate
	 * their address, and they didn't send their address, then we
	 * send a NAK with a CI_ADDR option appended.  We assume the
	 * input buffer is long enough that we can append the extra
	 * option safely.
	 */
	if(rc != CONFREJ && !ho->neg_addr && !ho->old_addrs &&
	        wo->req_addr && !reject_if_disagree && !pcb->settings.noremoteip) {
		if(rc == CONFACK) {
			rc = CONFNAK;
			ucp = inp;			/* reset pointer */
			wo->req_addr = 0;		/* don't ask again */
		}

		PUTCHAR(CI_ADDR, ucp);
		PUTCHAR(CILEN_ADDR, ucp);
		tl = lwip_ntohl(wo->hisaddr);
		PUTLONG(tl, ucp);
	}

	*len = ucp - inp;			/* Compute output length */
	IPCPDEBUG(("ipcp: returning Configure-%s", CODENAME(rc)));
	return (rc);			/* Return final code */
}


#if 0 /* UNUSED */
/*
 * ip_check_options - check that any IP-related options are OK,
 * and assign appropriate defaults.
 */
static void
ip_check_options()
{
	struct hostent* hp;
	u32_t local;
	ipcp_options* wo = &ipcp_wantoptions[0];

	/*
	 * Default our local IP address based on our hostname.
	 * If local IP address already given, don't bother.
	 */
	if(wo->ouraddr == 0 && !disable_defaultip) {
		/*
		 * Look up our hostname (possibly with domain name appended)
		 * and take the first IP address as our local IP address.
		 * If there isn't an IP address for our hostname, too bad.
		 */
		wo->accept_local = 1;	/* don't insist on this default value */

		if((hp = gethostbyname(hostname)) != NULL) {
			local = *(u32_t*)hp->h_addr;

			if(local != 0 && !bad_ip_adrs(local))
				wo->ouraddr = local;
		}
	}

	ask_for_local = wo->ouraddr != 0 || !disable_defaultip;
}
#endif /* UNUSED */

#if DEMAND_SUPPORT
/*
 * ip_demand_conf - configure the interface as though
 * IPCP were up, for use with dial-on-demand.
 */
static int
ip_demand_conf(u)
int u;
{
	ppp_pcb* pcb = &ppp_pcb_list[u];
	ipcp_options* wo = &ipcp_wantoptions[u];

	if(wo->hisaddr == 0 && !pcb->settings.noremoteip) {
		/* make up an arbitrary address for the peer */
		wo->hisaddr = lwip_htonl(0x0a707070 + ifunit);
		wo->accept_remote = 1;
	}

	if(wo->ouraddr == 0) {
		/* make up an arbitrary address for us */
		wo->ouraddr = lwip_htonl(0x0a404040 + ifunit);
		wo->accept_local = 1;
		ask_for_local = 0;	/* don't tell the peer this address */
	}

	if(!sifaddr(pcb, wo->ouraddr, wo->hisaddr, get_mask(wo->ouraddr)))
		return 0;

	if(!sifup(pcb))
		return 0;

	if(!sifnpmode(pcb, PPP_IP, NPMODE_QUEUE))
		return 0;

#if 0 /* UNUSED */

	if(wo->default_route)
		if(sifdefaultroute(pcb, wo->ouraddr, wo->hisaddr,
		                   wo->replace_default_route))
			default_route_set[u] = 1;

#endif /* UNUSED */
#if 0 /* UNUSED - PROXY ARP */

	if(wo->proxy_arp)
		if(sifproxyarp(pcb, wo->hisaddr))
			proxy_arp_set[u] = 1;

#endif /* UNUSED - PROXY ARP */

	ppp_notice("local  IP address %I", wo->ouraddr);

	if(wo->hisaddr)
		ppp_notice("remote IP address %I", wo->hisaddr);

	return 1;
}
#endif /* DEMAND_SUPPORT */

/*
 * ipcp_up - IPCP has come UP.
 *
 * Configure the IP network interface appropriately and bring it up.
 */
static void ipcp_up(fsm* f)
{
	ppp_pcb* pcb = f->pcb;
	u32_t mask;
	ipcp_options* ho = &pcb->ipcp_hisoptions;
	ipcp_options* go = &pcb->ipcp_gotoptions;
	ipcp_options* wo = &pcb->ipcp_wantoptions;

	IPCPDEBUG(("ipcp: up"));

	/*
	 * We must have a non-zero IP address for both ends of the link.
	 */
	if(!ho->neg_addr && !ho->old_addrs)
		ho->hisaddr = wo->hisaddr;

	if(!(go->neg_addr || go->old_addrs) && (wo->neg_addr || wo->old_addrs)
	        && wo->ouraddr != 0) {
		ppp_error("Peer refused to agree to our IP address");
		ipcp_close(f->pcb, "Refused our IP address");
		return;
	}

	if(go->ouraddr == 0) {
		ppp_error("Could not determine local IP address");
		ipcp_close(f->pcb, "Could not determine local IP address");
		return;
	}

	if(ho->hisaddr == 0 && !pcb->settings.noremoteip) {
		ho->hisaddr = lwip_htonl(0x0a404040);
		ppp_warn("Could not determine remote IP address: defaulting to %I",
		         ho->hisaddr);
	}

#if 0 /* UNUSED */
	script_setenv("IPLOCAL", ip_ntoa(go->ouraddr), 0);

	if(ho->hisaddr != 0)
		script_setenv("IPREMOTE", ip_ntoa(ho->hisaddr), 1);

#endif /* UNUSED */

#if LWIP_DNS

	if(!go->req_dns1)
		go->dnsaddr[0] = 0;

	if(!go->req_dns2)
		go->dnsaddr[1] = 0;

#if 0 /* UNUSED */

	if(go->dnsaddr[0])
		script_setenv("DNS1", ip_ntoa(go->dnsaddr[0]), 0);

	if(go->dnsaddr[1])
		script_setenv("DNS2", ip_ntoa(go->dnsaddr[1]), 0);

#endif /* UNUSED */

	if(pcb->settings.usepeerdns && (go->dnsaddr[0] || go->dnsaddr[1])) {
		sdns(pcb, go->dnsaddr[0], go->dnsaddr[1]);
#if 0 /* UNUSED */
		script_setenv("USEPEERDNS", "1", 0);
		create_resolv(go->dnsaddr[0], go->dnsaddr[1]);
#endif /* UNUSED */
	}

#endif /* LWIP_DNS */

	/*
	 * Check that the peer is allowed to use the IP address it wants.
	 */
	if(ho->hisaddr != 0) {
		u32_t addr = lwip_ntohl(ho->hisaddr);

		if((addr >> IP_CLASSA_NSHIFT) == IP_LOOPBACKNET
		        || IP_MULTICAST(addr) || IP_BADCLASS(addr)
		        /*
		         * For now, consider that PPP in server mode with peer required
		         * to authenticate must provide the peer IP address, reject any
		         * IP address wanted by peer different than the one we wanted.
		         */
#if PPP_SERVER && PPP_AUTH_SUPPORT
		        || (pcb->settings.auth_required && wo->hisaddr != ho->hisaddr)
#endif /* PPP_SERVER && PPP_AUTH_SUPPORT */
		  ) {
			ppp_error("Peer is not authorized to use remote address %I", ho->hisaddr);
			ipcp_close(pcb, "Unauthorized remote IP address");
			return;
		}
	}

#if 0 /* Unused */

	/* Upstream checking code */
	if(ho->hisaddr != 0 && !auth_ip_addr(f->unit, ho->hisaddr)) {
		ppp_error("Peer is not authorized to use remote address %I", ho->hisaddr);
		ipcp_close(f->unit, "Unauthorized remote IP address");
		return;
	}

#endif /* Unused */

#if VJ_SUPPORT
	/* set tcp compression */
	sifvjcomp(pcb, ho->neg_vj, ho->cflag, ho->maxslotindex);
#endif /* VJ_SUPPORT */

#if DEMAND_SUPPORT

	/*
	 * If we are doing dial-on-demand, the interface is already
	 * configured, so we put out any saved-up packets, then set the
	 * interface to pass IP packets.
	 */
	if(demand) {
		if(go->ouraddr != wo->ouraddr || ho->hisaddr != wo->hisaddr) {
			ipcp_clear_addrs(f->unit, wo->ouraddr, wo->hisaddr,
			                 wo->replace_default_route);

			if(go->ouraddr != wo->ouraddr) {
				ppp_warn("Local IP address changed to %I", go->ouraddr);
				script_setenv("OLDIPLOCAL", ip_ntoa(wo->ouraddr), 0);
				wo->ouraddr = go->ouraddr;
			} else
				script_unsetenv("OLDIPLOCAL");

			if(ho->hisaddr != wo->hisaddr && wo->hisaddr != 0) {
				ppp_warn("Remote IP address changed to %I", ho->hisaddr);
				script_setenv("OLDIPREMOTE", ip_ntoa(wo->hisaddr), 0);
				wo->hisaddr = ho->hisaddr;
			} else
				script_unsetenv("OLDIPREMOTE");

			/* Set the interface to the new addresses */
			mask = get_mask(go->ouraddr);

			if(!sifaddr(pcb, go->ouraddr, ho->hisaddr, mask)) {
#if PPP_DEBUG
				ppp_warn("Interface configuration failed");
#endif /* PPP_DEBUG */
				ipcp_close(f->unit, "Interface configuration failed");
				return;
			}

			/* assign a default route through the interface if required */
			if(ipcp_wantoptions[f->unit].default_route)
				if(sifdefaultroute(pcb, go->ouraddr, ho->hisaddr,
				                   wo->replace_default_route))
					default_route_set[f->unit] = 1;

#if 0 /* UNUSED - PROXY ARP */

			/* Make a proxy ARP entry if requested. */
			if(ho->hisaddr != 0 && ipcp_wantoptions[f->unit].proxy_arp)
				if(sifproxyarp(pcb, ho->hisaddr))
					proxy_arp_set[f->unit] = 1;

#endif /* UNUSED - PROXY ARP */

		}

		demand_rexmit(PPP_IP, go->ouraddr);
		sifnpmode(pcb, PPP_IP, NPMODE_PASS);

	} else
#endif /* DEMAND_SUPPORT */
	{
		/*
		 * Set IP addresses and (if specified) netmask.
		 */
		mask = get_mask(go->ouraddr);

#if !(defined(SVR4) && (defined(SNI) || defined(__USLC__)))

		if(!sifaddr(pcb, go->ouraddr, ho->hisaddr, mask)) {
#if PPP_DEBUG
			ppp_warn("Interface configuration failed");
#endif /* PPP_DEBUG */
			ipcp_close(f->pcb, "Interface configuration failed");
			return;
		}

#endif

		/* bring the interface up for IP */
		if(!sifup(pcb)) {
#if PPP_DEBUG
			ppp_warn("Interface failed to come up");
#endif /* PPP_DEBUG */
			ipcp_close(f->pcb, "Interface configuration failed");
			return;
		}

#if (defined(SVR4) && (defined(SNI) || defined(__USLC__)))

		if(!sifaddr(pcb, go->ouraddr, ho->hisaddr, mask)) {
#if PPP_DEBUG
			ppp_warn("Interface configuration failed");
#endif /* PPP_DEBUG */
			ipcp_close(f->unit, "Interface configuration failed");
			return;
		}

#endif
#if DEMAND_SUPPORT
		sifnpmode(pcb, PPP_IP, NPMODE_PASS);
#endif /* DEMAND_SUPPORT */

#if 0 /* UNUSED */

		/* assign a default route through the interface if required */
		if(wo->default_route)
			if(sifdefaultroute(pcb, go->ouraddr, ho->hisaddr,
			                   wo->replace_default_route))
				pcb->default_route_set = 1;

#endif /* UNUSED */

#if 0 /* UNUSED - PROXY ARP */

		/* Make a proxy ARP entry if requested. */
		if(ho->hisaddr != 0 && wo->proxy_arp)
			if(sifproxyarp(pcb, ho->hisaddr))
				pcb->proxy_arp_set = 1;

#endif /* UNUSED - PROXY ARP */

		wo->ouraddr = go->ouraddr;

		ppp_notice("local  IP address %I", go->ouraddr);

		if(ho->hisaddr != 0)
			ppp_notice("remote IP address %I", ho->hisaddr);

#if LWIP_DNS

		if(go->dnsaddr[0])
			ppp_notice("primary   DNS address %I", go->dnsaddr[0]);

		if(go->dnsaddr[1])
			ppp_notice("secondary DNS address %I", go->dnsaddr[1]);

#endif /* LWIP_DNS */
	}

#if PPP_STATS_SUPPORT
	reset_link_stats(f->unit);
#endif /* PPP_STATS_SUPPORT */

	np_up(pcb, PPP_IP);
	pcb->ipcp_is_up = 1;

#if PPP_NOTIFY
	notify(ip_up_notifier, 0);
#endif /* PPP_NOTIFY */
#if 0 /* UNUSED */

	if(ip_up_hook)
		ip_up_hook();

#endif /* UNUSED */
}


/*
 * ipcp_down - IPCP has gone DOWN.
 *
 * Take the IP network interface down, clear its addresses
 * and delete routes through it.
 */
static void ipcp_down(fsm* f)
{
	ppp_pcb* pcb = f->pcb;
	ipcp_options* ho = &pcb->ipcp_hisoptions;
	ipcp_options* go = &pcb->ipcp_gotoptions;

	IPCPDEBUG(("ipcp: down"));
#if PPP_STATS_SUPPORT
	/* XXX a bit IPv4-centric here, we only need to get the stats
	 * before the interface is marked down. */
	/* XXX more correct: we must get the stats before running the notifiers,
	 * at least for the radius plugin */
	update_link_stats(f->unit);
#endif /* PPP_STATS_SUPPORT */
#if PPP_NOTIFY
	notify(ip_down_notifier, 0);
#endif /* PPP_NOTIFY */
#if 0 /* UNUSED */

	if(ip_down_hook)
		ip_down_hook();

#endif /* UNUSED */

	if(pcb->ipcp_is_up) {
		pcb->ipcp_is_up = 0;
		np_down(pcb, PPP_IP);
	}

#if VJ_SUPPORT
	sifvjcomp(pcb, 0, 0, 0);
#endif /* VJ_SUPPORT */

#if PPP_STATS_SUPPORT
	print_link_stats(); /* _after_ running the notifiers and ip_down_hook(),
			 * because print_link_stats() sets link_stats_valid
			 * to 0 (zero) */
#endif /* PPP_STATS_SUPPORT */

#if DEMAND_SUPPORT

	/*
	 * If we are doing dial-on-demand, set the interface
	 * to queue up outgoing packets (for now).
	 */
	if(demand) {
		sifnpmode(pcb, PPP_IP, NPMODE_QUEUE);
	} else
#endif /* DEMAND_SUPPORT */
	{
#if DEMAND_SUPPORT
		sifnpmode(pcb, PPP_IP, NPMODE_DROP);
#endif /* DEMAND_SUPPORT */
		sifdown(pcb);
		ipcp_clear_addrs(pcb, go->ouraddr,
		                 ho->hisaddr, 0);
#if LWIP_DNS
		cdns(pcb, go->dnsaddr[0], go->dnsaddr[1]);
#endif /* LWIP_DNS */
	}
}


/*
 * ipcp_clear_addrs() - clear the interface addresses, routes,
 * proxy arp entries, etc.
 */
static void ipcp_clear_addrs(ppp_pcb* pcb, u32_t ouraddr, u32_t hisaddr, u8_t replacedefaultroute)
{
	LWIP_UNUSED_ARG(replacedefaultroute);

#if 0 /* UNUSED - PROXY ARP */

	if(pcb->proxy_arp_set) {
		cifproxyarp(pcb, hisaddr);
		pcb->proxy_arp_set = 0;
	}

#endif /* UNUSED - PROXY ARP */
#if 0 /* UNUSED */

	/* If replacedefaultroute, sifdefaultroute will be called soon
	 * with replacedefaultroute set and that will overwrite the current
	 * default route. This is the case only when doing demand, otherwise
	 * during demand, this cifdefaultroute would restore the old default
	 * route which is not what we want in this case. In the non-demand
	 * case, we'll delete the default route and restore the old if there
	 * is one saved by an sifdefaultroute with replacedefaultroute.
	 */
	if(!replacedefaultroute && pcb->default_route_set) {
		cifdefaultroute(pcb, ouraddr, hisaddr);
		pcb->default_route_set = 0;
	}

#endif /* UNUSED */
	cifaddr(pcb, ouraddr, hisaddr);
}


/*
 * ipcp_finished - possibly shut down the lower layers.
 */
static void ipcp_finished(fsm* f)
{
	ppp_pcb* pcb = f->pcb;

	if(pcb->ipcp_is_open) {
		pcb->ipcp_is_open = 0;
		np_finished(pcb, PPP_IP);
	}
}


#if 0 /* UNUSED */
/*
 * create_resolv - create the replacement resolv.conf file
 */
static void
create_resolv(peerdns1, peerdns2)
u32_t peerdns1, peerdns2;
{

}
#endif /* UNUSED */

#if PRINTPKT_SUPPORT
/*
 * ipcp_printpkt - print the contents of an IPCP packet.
 */
static const char* const ipcp_codenames[] = {
	"ConfReq", "ConfAck", "ConfNak", "ConfRej",
	"TermReq", "TermAck", "CodeRej"
};

static int ipcp_printpkt(const u_char* p, int plen,
                         void (*printer)(void*, const char*, ...), void* arg)
{
	int code, id, len, olen;
	const u_char* pstart, *optend;
#if VJ_SUPPORT
	u_short cishort;
#endif /* VJ_SUPPORT */
	u32_t cilong;

	if(plen < HEADERLEN)
		return 0;

	pstart = p;
	GETCHAR(code, p);
	GETCHAR(id, p);
	GETSHORT(len, p);

	if(len < HEADERLEN || len > plen)
		return 0;

	if(code >= 1 && code <= (int)LWIP_ARRAYSIZE(ipcp_codenames))
		printer(arg, " %s", ipcp_codenames[code - 1]);
	else
		printer(arg, " code=0x%x", code);

	printer(arg, " id=0x%x", id);
	len -= HEADERLEN;

	switch(code) {
		case CONFREQ:
		case CONFACK:
		case CONFNAK:
		case CONFREJ:

			/* print option list */
			while(len >= 2) {
				GETCHAR(code, p);
				GETCHAR(olen, p);
				p -= 2;

				if(olen < 2 || olen > len) {
					break;
				}

				printer(arg, " <");
				len -= olen;
				optend = p + olen;

				switch(code) {
					case CI_ADDRS:
						if(olen == CILEN_ADDRS) {
							p += 2;
							GETLONG(cilong, p);
							printer(arg, "addrs %I", lwip_htonl(cilong));
							GETLONG(cilong, p);
							printer(arg, " %I", lwip_htonl(cilong));
						}

						break;
#if VJ_SUPPORT

					case CI_COMPRESSTYPE:
						if(olen >= CILEN_COMPRESS) {
							p += 2;
							GETSHORT(cishort, p);
							printer(arg, "compress ");

							switch(cishort) {
								case IPCP_VJ_COMP:
									printer(arg, "VJ");
									break;

								case IPCP_VJ_COMP_OLD:
									printer(arg, "old-VJ");
									break;

								default:
									printer(arg, "0x%x", cishort);
							}
						}

						break;
#endif /* VJ_SUPPORT */

					case CI_ADDR:
						if(olen == CILEN_ADDR) {
							p += 2;
							GETLONG(cilong, p);
							printer(arg, "addr %I", lwip_htonl(cilong));
						}

						break;
#if LWIP_DNS

					case CI_MS_DNS1:
					case CI_MS_DNS2:
						p += 2;
						GETLONG(cilong, p);
						printer(arg, "ms-dns%d %I", (code == CI_MS_DNS1 ? 1 : 2),
						        htonl(cilong));
						break;
#endif /* LWIP_DNS */
#if 0 /* UNUSED - WINS */

					case CI_MS_WINS1:
					case CI_MS_WINS2:
						p += 2;
						GETLONG(cilong, p);
						printer(arg, "ms-wins %I", lwip_htonl(cilong));
						break;
#endif /* UNUSED - WINS */

					default:
						break;
				}

				while(p < optend) {
					GETCHAR(code, p);
					printer(arg, " %.2x", code);
				}

				printer(arg, ">");
			}

			break;

		case TERMACK:
		case TERMREQ:
			if(len > 0 && *p >= ' ' && *p < 0x7f) {
				printer(arg, " ");
				ppp_print_string(p, len, printer, arg);
				p += len;
				len = 0;
			}

			break;

		default:
			break;
	}

	/* print the rest of the bytes in the packet */
	for(; len > 0; --len) {
		GETCHAR(code, p);
		printer(arg, " %.2x", code);
	}

	return p - pstart;
}
#endif /* PRINTPKT_SUPPORT */

#if DEMAND_SUPPORT
/*
 * ip_active_pkt - see if this IP packet is worth bringing the link up for.
 * We don't bring the link up for IP fragments or for TCP FIN packets
 * with no data.
 */
#define IP_HDRLEN	20	/* bytes */
#define IP_OFFMASK	0x1fff
#ifndef IPPROTO_TCP
	#define IPPROTO_TCP	6
#endif
#define TCP_HDRLEN	20
#define TH_FIN		0x01

/*
 * We use these macros because the IP header may be at an odd address,
 * and some compilers might use word loads to get th_off or ip_hl.
 */

#define net_short(x)	(((x)[0] << 8) + (x)[1])
#define get_iphl(x)	(((unsigned char *)(x))[0] & 0xF)
#define get_ipoff(x)	net_short((unsigned char *)(x) + 6)
#define get_ipproto(x)	(((unsigned char *)(x))[9])
#define get_tcpoff(x)	(((unsigned char *)(x))[12] >> 4)
#define get_tcpflags(x)	(((unsigned char *)(x))[13])

static int
ip_active_pkt(pkt, len)
u_char* pkt;
int len;
{
	u_char* tcp;
	int hlen;

	len -= PPP_HDRLEN;
	pkt += PPP_HDRLEN;

	if(len < IP_HDRLEN)
		return 0;

	if((get_ipoff(pkt) & IP_OFFMASK) != 0)
		return 0;

	if(get_ipproto(pkt) != IPPROTO_TCP)
		return 1;

	hlen = get_iphl(pkt) * 4;

	if(len < hlen + TCP_HDRLEN)
		return 0;

	tcp = pkt + hlen;

	if((get_tcpflags(tcp) & TH_FIN) != 0 && len == hlen + get_tcpoff(tcp) * 4)
		return 0;

	return 1;
}
#endif /* DEMAND_SUPPORT */

#endif /* PPP_SUPPORT && PPP_IPV4_SUPPORT */
